Portable rotary hammer.



l C. LEONARDI.

PORTABLE ROTARY HAMMER.

APPLIOATION FILED 11,415.25. 1915l 1,094,664, Patented. Apr'. 28, 1914.

2 SHEETS-SHEET 1.

G. LEONARDI.

PORTABLE ROTARY HAMMER.

APPLICATION FILED MAR. 2s, 1913.

Patented M1128, 1914.

2 SHEETS-SHEET 2.

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PORTABLE ROTARY HAMMER.

To all whom it may concern.'

Be it known that I, CARLO LEONARDI, a subject of the Italian King, andresident of Milan, Italy, have invented certain new and usefulImprovements in Portable Rotary Hammers.

The present invention has for its object to provide a portable rotaryhammer, the handle of which is jointed to the hub of a driven shaft, thenovelty residing in the fact that the heads in the form of one or morespheres or other shaped bodies, is jointed by means of two laterallevers to the hub of the rotary shaft the journals of which rotate inthe bearings of the two circular detachable lateral cheeks of an annularbox semi circular in cross section and to which a tubular socket isfixed; the handle of the tool is guided in this socket and its upperextremity projects into the interior of the box so that the head of thehammer or hammers strike it in rapid succession.

An embodiment of the invention is illustrated by way of example in theaccompanying drawing, in which:

Figure 1 is a partial section at right angles to the axis of theapparatus. Fig. 2 shows the interior of the apparatus and one of thehalves of the casing, the other being omitted.

A hub 2 is keyed upon the driven shaft 1 or may be integral therewith;in the construction here illustrated this hub carries three radial arms3 each ending in a bearing et through which a pivot 5 passes; this pivotis provided with two lateral heads 6 serving to maintain in place twolateral arms 7 con stituting the hammer handle proper, their oppositeextremities being connected by a spindle 8 upon which the head of thehammer rotates freely; in the present case this head is constituted by aspherical part 9. rlhe mass of each hammer is cylindrical in the partlocated in the median plane of the apparatus and perpendicular to theshaft 1. The latter, or its journals rotate freely in the bearings 10 oftwo circular lateral cheeks 11 held between the two halves 12 and 13 ofthe annular casing of semi-circular cross section. These two segmentalparts 12 and 13 are hinged together at 14 and held together by means ofan extended spiral spring 15 the extremities of which are xed to thepivots 16 of two arms 17 cast with each of the halves 12 and 13respectively.

Specification of Letters Patent.

Application filed March 25, 1918.

Patented Apr. 28, 1914. Serial No. 756,804.

One of these halves (12) is provided in proximity to the hinge 14 and infront thereof, with a tubular socket 18 lined with a socket 19, havingan opening in the bottom 20, and in which a second socket 21 is able toslide freely; the shank 22 of a tool of any kind, such for example as achipping chisel, a mandrel, a die or the like is fixed in this socket 21with its end projecting through the perforated bottom 20 of the socket19 into the interior of the casing 12. The spiral spring referred toabove serves also as a handle for facilitating manipulation of theapparatus.

The operation of the apparatus is as follows: A rapid movement ofrotation is imparted to the driven shaft 1 in such a manner that thehammers pivoted to its hub rotate at the same speed. The heads of thehammers strike in rapid succession upon the upper extremity of the shank22 of the tool which projects into the interior of the casing 12.

In view of the fact that the socket 21 is able to slide freely in theinterior of the socket 19, it is possible to regulate the intervalseparating the shank of the tool from the heads of the hammers andthereby regulate the force of each blow.

The shaft 1 can be controlled mechanically or by hand; if it is drivenby a motor, the latter can be mounted directly upon the casing or itsdriving shaft can be connected by a flexible shaft with the shaft 1 ifthe motor is mounted at a distance.

I claim:

In a device of the kind described, a casing, a shaft journaled in saidcasing, a hub mounted on said shaft, a series of arms pivoted to saidhub and arranged in pairs, a hammer head journaled between each pair ofarms, a tubular socket extending from said casing and a tool holderslidably mounted in said socket and arranged to receive the shank of atool and hold the same in the path of said head, said tool holder beingmovable to vary the position of the shank with relation to said head.

In testimony whereof I have hereunto set my hand in presence of twowitnesses.

CARLO LEONARDI.

Witnesses SALVATORE DANIELLI, PATRICK JOI-IN KEELAN.

Copies of this patent may be obtained for ive cents each, by addressingthe Commissioner of IPatents,

Washington, D. C.

